tbuckley/cabot-search huggingface dataset:
P20.02.B ELECTRO-CLINICAL, NEUROIMAGING FEATURES AND NEUROPATHOLOGICAL CHARACTERIZATION OF POLYMORPHOUS LOW-GRADE NEUROEPITHELIAL TUMOR OF THE YOUNG (PLNTY)
Authors: E Anghileri, G Didato, F Deleo, F M Doniselli, M Moscatelli, M Rizzi, R Paterra, M de Curtis, M Farinotti, E Freri, S Esposito, B Pollo, A Silvani, G Marucci
Journal: Neuro-Oncology (2023)

Abstract BACKGROUND Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) has been recently recognized by 2021 WHO Central nervous system classification. It is an epileptogenic tumor type, affecting mostly children and young adults, with peculiar radiological, and pathomolecular features. PLNTY is a very rare tumor, described in only 52 cases up to now. Herein, we describe 13 patients with electro-clinical and neuroimaging findings, associated to histopathological and molecular findings. MATERIAL AND METHODS We selected PLNTY patients from our Cancer Registry (Apr 2017-Dec 2022), and collected electro-clinical, radiological and histo-molecular data. Minimum follow-up was 6 months. Exams included EEG, long-term scalp video-EEG, pre-surgical brain computer tomography and Magnetic Brain Imaging (MRI). Immunohistochemistry included CD34, IDH1-R132H, GFAP, synaptophysin, ATRX, p53 and FGFR3. IDH1-2, BRAF (V600E) sequencing, Kiaa1549:BRAF, FGFR3:TACC3, FGFR2:kii1598 and FGFR2:CTNNA3 fusion analyses will be performed. RESULTS We describe 13 patients, median age 20.6 years (range 12.3-46.4). Most patients showed memory/executive impairment and had epilepsy, with an onset from 5 months-21 years before surgery. The main feature of seizures was a difficult localization and even lateralization, both semiologically and electrographically. Post-surgical seizure control was excellent.The tumors (n=11/13 temporal) presented as solid or solid-cystic cortical mass with no mass effect and unclear hedges. Calcifications were present in 4, and cysts in 6 cases. Microscopically the tumors showed infiltrative growth pattern, oligodendroglial-like cells, strong and often diffuse CD34 immunostaining, and frequent intra-tumoral calcifications. Malformation of cortical development, namely FCD type IIIB, was associated to PLNTY in 2 cases. Proliferation activity (MIB-1 LI) was very low (1%) in all cases except one (MIB-1 LI which reached 3%). CONCLUSION This study significantly extends the number of reported PLNTY associated to epilepsy, mostly characterized by bilateral interictal epileptiform discharges and difficult to lateralize seizures.The MRI features were heterogeneous and the differential diagnosis should include also dysplasia and glioneuronal tumors. PLNTY, despite its name, occurs also in adults, and electro-clinical and radiological diagnosis can be challenging. As recently described, PLNTY can show the MAPK pathway activating alterations, that are under investigation in our cohort to eventually clarify their role in the evolution of the disease. SUPPORT the study is partially supported by the Health Italian Minister (RC).
P11.53.B MOLECULAR PROFILING AND ACTIONABLE MUTATIONS IN ADULT PATIENTS WITH IDH WILD TYPE GLIOMAS AND GLIONEURONAL AND NEURONAL TUMORS
Authors: A Pellerino, E Marchesani, L Bertero, A Ricci, L Mangherini, F Bruno, R Soffietti, R Rudà
Journal: Neuro-Oncology (2023)

Abstract BACKGROUND Next generation sequencing (NGS) assays enable the identification of genetic alterations that may guide a personalized treatment in glioma patients. MATERIAL AND METHODS From July 2021 to March 2023 a NGS analysis (Myriapod® NGS Cancer DNA and RNA panels) was performed in a large prospective cohort of adults with an histological diagnosis of IDH wild type glioma or circumscribed astrocytoma or glioneuronal and neuronal tumor at the Division of Neuro-Oncology, University and City of Health and Science Hospital, Turin, Italy. The aim was to identify potential actionable molecular alterations and provide targeted therapy at recurrence accordingly. RESULTS We collected tumor samples from 221 patients. NGS analysis was available in 211 patients (95.5%), while NGS was not feasible in 10 patients (4.5%). 188 patients out of 211 (89.1%) had an IDH wild type glioblastoma (GBM) (median age 61 years, range 24-84; F/M: 97/91), 6 patients (2.8%) had IDH wild type lower grade gliomas (LGG) (median age 63 years, range 43-78; F/M: 3/3), and 17 patients (8.1%) had circumscribed astrocytoma or glioneuronal and neuronal tumor (median age 37 years, range 18-67; F/M: 13/4). Overall, actionable molecular alterations were found in 13/211 patients (6.2%). In this regard, 7/211 patients (3.3%) had BRAF V600E mutation (3 IDH wild type GBM, 1 IDH wild type LGG, and 3 circumscribed/glioneuronal and neuronal tumor), 4/211 patients (1.9%) had FGFR3-TACC3 fusion (all GBM), 1/211 patients (0.5%) had PIK3CA mutation (GBM), and 1/211 patients (0.5%) had NTRK1 fusion (glioneuronal tumor). Other molecular mutations, including ALK, ERBB2, MET, KIT, KRAS, PDGFRA, and RET have not been detected in our cohort. Three patients with druggable mutations recurred after first-line therapy: 1 patient with BRAF mutated GBM, 1 patient with GBM harboring FGFR3-TACC3 fusion, and 1 patient with NTRK1 fusion positive glioneuronal tumor received specific BRAF/MEK inhibitor (dabrafenib/trametinib), FGFR inhibitor (pemigatinib), and NTRK inhibitor (larotrectinib), respectively. A remarkable activity of BRAF/MEK and NTRK inhibitors was observed (8 months and 5 months, respectively *), while FGFR inhibitor did not display a significant activity to control disease (9 weeks). * ongoing CONCLUSION The incidence of actionable molecular alterations in IDH wild type gliomas and glioneuronal and neuronal tumors was low. However, the possibility of using targeted therapies may lead to an important impact on the outcome.
P06.04.B NEW APPROACHES FOR EXPANDING GLIOBLASTOMA INFILTRATING LYMPHOCYTES
Authors: M Khasraw, K Hotchkiss, E Blandford, A Mohan, C Railton, M Brown, P Noldner, Y Zhou, R Parrott, P Fecci, S Antonia, A Patel, B Shaz
Journal: Neuro-Oncology (2023)

Abstract BACKGROUND Adoptive cell therapy using tumor infiltrating lymphocytes (TILs) has shown promise in melanoma and Non-Small Cell Lung Cancer. TILs culture and expansion from GBM remains challenging due to paucity of infiltrated T-cells that are also exhausted. This hinders creation of potent TILs. We have developed a new efficient method to manufacture potent TILs from GBM samples. METHODS We have developed efficient TILs manufacturing methods using both solid and aspirated liquid samples collected during vacuum assisted excision containing tumor fragments that may stem predominantly from the tumor margins and provide a source for TILs. We followed the traditional two steps: initial expansion (preREP) where T-cells are expanded with tumor cells to selectively expand tumor antigen-reactive TILs, followed by a large-scale expansion (REP) after further activation. For both steps we optimized media and reagents. RESULTS TILs cultures from solid tumors were established from enzymatically digested tissue and by fragment plating. Successful TILs yield from liquid samples required enzymatic digestion, debris removal and RBC lysis prior to culture initiation. PreREP TILs yields ranged from a few million to 2 billion viable cells for solid and liquid samples. REP of TILs from liquid samples expanded similarly from solid samples. REP of TILs reached up to 556-fold expansion (mean: 346, range: 95-556) providing promising numbers of activated TILs. The potency of the TILs was demonstrated with tumor specific Interferon-gamma production when cultured with matched tumor digest or neurospheres. CONCLUSIONS We successfully expanded TILs that are rich in cytotoxic T-cells, demonstrated their tumor reactivity and further expanded the preREP TILs to reach therapeutic doses. We have characterized the TILs by scRNA and TCRseq and analyze paired TCR reads using scRNA sequencing. Overrepresented TCR alpha and beta chains will be linked by a P2A site and will be cloned into a lentiviral vector to establish a TCR library which will be transduced into novel Jurkat Triple Parameter Reporter Cell Lines under the control of different T cell activation programs. TCR Jurkat Libraries will be cocultured with original tumor material and sorted to identify tumor reactive TCRs; enabling us to define the percentage of TCRs that are enriched by TIL isolation that are specifically reactive to tumor vs bystander expanded TCR cells. Ultimately, we aim to bring this therapy to patients in a clinical trial.
P11.40.A GLIOBLASTOMA WITH OSSEOUS METASTASES: A SINGLE INSTITUTION CASE SERIES
Authors: L M Webb, M J Webb, J L Campian, S J Caron, U Sener
Journal: Neuro-Oncology (2023)

Abstract BACKGROUND Although glioblastoma (GBM) is the most common malignant primary brain tumor in adults, extracranial metastasis is rare, occurring in &amp;lt;2% of cases. This rarity has been attributed to the blood brain barrier, immunologic factors, lack of traditional lymphatics in the brain, and the poor prognosis of GBM, limiting its opportunity to metastasize. When GBM does metastasize, bone is the most common destination. GBM may spread hematogenously to bone, especially to vertebral bodies via the surrounding venous plexus. In this single-institution study, we review the clinical characteristics of GBM patients with osseous metastases and evaluate potential risk factors and prognostic significance. MATERIAL AND METHODS Using an institutional database, we identified and retrospectively analyzed 6 GBM patients with osseous metastases and studied their demographics, tumor genetics, clinical courses, and outcomes. RESULTS Five of 6 (83%) GBM patients with osseous metastases were male, with a median age of 46 years at GBM diagnosis (range: 20-84). All patients had IDH wild type and MGMT unmethylated GBM with mutations in TP53. Two patients (33%) were initially diagnosed with gliosarcoma. All patients were treated with surgical resection followed by radiation with concurrent and adjuvant temozolomide. Five patients (83%) received bevacizumab for vasogenic edema (n=4) or intracranial tumor progression (n=1) prior to bone metastasis diagnosis. Bone metastases were diagnosed a median of 12.2 months (range: 5.3-35.2) after GBM diagnosis and 4.8 months after starting bevacizumab (range: 3.5-13.2). Two patients (33%) received immune checkpoint inhibitor therapy and two patients (33%) received tumor-treating fields prior to bone metastasis discovery. Bone metastases were symptomatic in 2 patients, presenting with back pain (n=1) and leg weakness and urinary incontinence (n=1). Three patients (50%) had concurrent metastases to other organs. Osseous metastases were biopsy-confirmed in 3 (50%) cases, while the other 3 patients had no known alternative malignancy to explain their bone metastases. After osseous metastasis discovery, the median survival was 27 days (range: 13-225). CONCLUSION Most of our GBM patients with osseous metastases were male and most, but not all, were young at GBM diagnosis. Tumor genetics common to all patients included IDH wild type, MGMT unmethylated status, and TP53 mutation, which may be important for osseous metastasis. Most patients received bevacizumab, which may be associated with earlier metastasis. While rare, metastatic GBM should be within the differential for GBM patients with bone pain or progressive neurologic symptoms, as osseous metastases portend a dismal prognosis in an already aggressive malignancy.
P02.06.B DIELECTRIC PROPERTIES OF INTRACRANIAL TUMORS
Authors: M Proescholdt, A Haj, K Schebesch, C Doenitz, J Hoehne, N Schmidt
Journal: Neuro-Oncology (2023)

Abstract BACKGROUND Recently, tumor treating fields (TTFields) were established for the treatment of newly diagnosed glioblastoma (GBM). One of the most crucial parameters defining the treatment efficacy of TTFields is the electric field intensity, which depends on the dielectric properties of the tumor tissue. In this study we determined the dieclectric properties of brain tumors by analyzing resected tissue following a fast acquisition protocol. In GBM patients, histological analysis for cellularity, vascularization and myelin content was performed. In addition, sensitivity analyses for specific parameters (tissue hydration, temperature, and saline irrigation) were conducted. MATERIAL AND METHODS A cohort of 130 patients with tumors of different histology and malignancy grade have been recruited (meningioma: n=36; brain metastases n=29; low grade glioma n=7; anaplastic glioma = 12; other= 7; glioblastoma n=39, all treated with TTFields). Tissue samples were placed into a cylindrical cell with a known diameter. The impedance was recorded at frequencies 20Hz-1MHz using a software specifically developed for this study. The measured impedance was translated into dielectric properties of the sample (conductivity and relative permittivity) based on the parallel plate model. Myelin, which is the most powerful electric isolator in the brain, was assessed in GBM samples by luxol fast blue staining, and quantified in a three-tier scale. To assess the impact of tissue conditions on the measurements, probes were warmed to 35 degree Celsius, dehydrated or irrigated with 0.9% saline solution. RESULTS We found significant differences between the conductivity of different types of tumors with meningiomas showing the lowest and GBM tissue exhibiting the highest conductivity values. GBM samples with very high median conductivity values displayed a consistently lower myelin content. In addition, GBM patients with particularly high conductivity had a significantly shorter overall survival (log rank analysis, p = 0.024). While tissue temperature had no detectable effects on the dielectric properties in GBM, saline irrigation tissue hydration significantly affected the results. CONCLUSION The dielectric properties of intracranial tumors depend on histological class and malignancy grade. GBM patients with high conductivity values showed a significantly poorer prognosis, indicating this parameter as potential marker for TTF efficacy.
P04.10.A ASSESSMENT OF VDR STATUS BY IMMUNOHISTOCHEMISTRY IN CHILDHOOD MALIGNANCIES - VDR EXPRESSION PATTERN OF CNS TUMORS
Authors: O Juhász
Journal: Neuro-Oncology (2023)

Abstract BACKGROUND Childhood cancers, including CNS tumors, the second most prevalent entities after hematological malignancies cannot generally be prevented or identified through screening, the disease is often diagnosed at advanced stages, and this obviously affects patient outcomes negatively. There is an urgent need for identifying prognostic and therapeutic biomarkers. Our previous work has shown a correlation between lower vitamin D levels in children with cancer and adverse prognosis. VDR expression in childhood solid tumors has been linked to tumor characteristics and patient survival only in few studies, moreover literature found that VDR plays a role in the development of the central nervous system. METHODS For this study, 177 children with solid tumors were selected whose biopsies and tumor tissue formalin-fixed, paraffin-embedded tissue blocks were available for immunohistochemical (IHC) analysis at Semmelweis University, Budapest (Hungary). To investigate the association between the presence of VDR in the tumor tissue and outcome, tumor samples and the survival dataset of 110 children were available. RESULTS We found that minor VDR expression was associated with a significantly less favorable prognosis (p = 0.0061) in the examined childhood solid tumors. The rate of VDR expression differed significantly between tumor types (p &amp;lt;0.0001). In case of CNS tumors pathological observations on VDR expression characteristics partly not correlated with previous literature. In some ependymoma samples an utterly novel VDR pattern was observed. CONCLUSION In conclusion, VDR expression measured by IHC staining is inversely associated with aggressive characteristics in different childhood cancers. The downregulation of VDR expression in more aggressive childhood cancers suggests that functional vitamin D activity may slow or block cancer progression. The presence of VDR may have prognostic and therapeutic implications for CNS malignancies. Knowledge of the VDR status in childhood solid tumors provides clinicians with a valuable biomarker and based on this, additional therapy (vitamin D, and analogs) to use alongside conventional first-line oncotherapy.
P11.76.A SPECTRUM OF TP53 SOMATIC MUTATIONS IN A PROSPECTIVE STUDY OF PATIENTS WITH GLIOMA
Authors: S Cabezas-Camarero, R Pérez-Alfayate, V García-Barberán, M Gandía, P García-Feijóo, I López-Cade, M J Sotelo, M Cerón, I Casado-Fariñas, P Pérez-Segura
Journal: Neuro-Oncology (2023)

Abstract BACKGROUND TP53 mutations occur frequently in gliomas, being most common in IDH-wild-type (WT) glioblastomas (GB) and in IDH-mutant (MUT) oligodendrogliomas (OD). Our aim was to describe the mutation spectrum of TP53 somatic mutations in patients (pts) with glioma. MATERIAL AND METHODS This was a prospective multicenter study of patients with glioma diagnosed at four different institutions in Spain. Next-generation sequencing (NGS) of formalin-fixed paraffin-embedded (FFPE) or fresh tumor samples were used for sequencing the TP53 gene in an Illumina Miseq instrument (Illumina, Inc.). Only TP53 pathogenic mutations were considered as valid and are reported here. RESULTS Between February 2017 and March 2020, 61 glioma patients (pts) were enrolled among which 17 different pathogenic mutations in TP53 were detected. Mutant allele frequency (MAF) was &amp;gt; 4% in all cases. TP53 pathogenic mutations occurred at the following loci: L145P, R158H, R175H, H193R, G199V, R202C, R213X, H214R, Y234C, R248Q, I255S, E271Vfs*36, R273C, P278T, G278T, G279E, R280K. Additional clinical characteristics and survival results will be presented at the meeting. CONCLUSION TP53 occur frequently in glioma but widely distributed across the whole exome. The contribution of each specific pathogenic TP53 mutation in gliomas should be further studied.
P02.20.B PLASMA MEMBRANE-ASSOCIATED 70 KDA HEAT SHOCK PROTEIN (HSP70) INVOLVED IN GLIOBLASTOMA CELLS INVASION AS A TARGET FOR TUMOR THERANOSTICS
Authors: M Shevtsov, N Yudintceva, D Bobkov, R Tagaeva, K Samochernykh, A Kim, A Nechaeva, E Fedorov, V Fedorov, E Nazaralieva, A Ten, S E Combs
Journal: Neuro-Oncology (2023)

Abstract BACKGROUND Heat shock proteins (HSPs) represent a large family of highly conserved proteins serving as molecular chaperones that play an important role in intracellular homeostasis. Apart from their intracellular localization, members of various HSPs families such as HSP70 have been reported to be expressed on the plasma membrane of malignant cells, including glioblastoma multiforme (GBM). However, the role of the membrane-bound protein Hsp70 has not yet been investigated in the pathophysiology of GBM. MATERIAL AND METHODS mHsp70 expression as related to GBM cell invasive potential was analyzed in biopsies obtained from neurooncological patients using CellVoyager CQ1 Benchtop High-Content Analysis System (Yokogawa) and inverted confocal microscopy (Leica Microsystems). Application of membrane-associated chaperone for targeted therapies was assessed in the intracranial human NCH644, NCH421k, and U87 GBM models in immunodeficient mice employing various chaperone inhibitors (i.e., JG-98, MKT-077, pifithrin-μ (PES)) as a monotherapy or in combination with a single dose of stereotactic irradiation (10Gy) (SARRP). RESULTS Live-cell imaging of the patient-derived biopsies demonstrated the increased cellular density of mHsp70+ GBM cells particularly in the tissue along the tumor-brain margin. Time-lapse evaluation of the tumor sample further proved the migration of mHsp70+ cells into the surrounding normal brain tissues. Subsequent high-powered multiplex immunofluorescence analysis (Akoya Biosystems) confirmed significantly increased single-cell infiltration of mHsp70+ tumor cells (also positively stained for Nestin, Oct4, and SOX2) in the normal brain tissues. When mHsp70 inhibitors were applied in GBM animal models as a monotherapy or in combination with radiotherapy dramatic inhibition of tumor progression (as shown by MRI) and increased animal survival were observed. CONCLUSION Expression of the mHsp70 on the plasma membrane of GBM cells corresponds to the highly invasive potential of the tumor cells in neuro-oncological patients. Administration of the HSP70 small molecular inhibitors significantly decreased the GBM growth and invasion thus prolonging the overall survival of tumor-bearing mice. Further development of mHsp70-targeted agents represents a promising approach in treatment of multiforme glioblastoma.
P03.13.B RADIOTHERAPY-INDUCED COGNITIVE IMPAIRMENT IN CANCER PATIENTS: IS SENESCENCE INVOLVED?
Authors: L E Kuil, M C de Gooijer, C van Heijningen, A Compter, O van Tellingen, S B Schagen
Journal: Neuro-Oncology (2023)

Abstract BACKGROUND Patients with primary and metastatic brain tumors that survive may experience cognitive problems including progressive impairments in memory, attention, and executive function attributed to radiation-induced brain injury. Irradiation is known to bring tumor cells into senescence, a state of permanent proliferation arrest that is accompanied by metabolic changes and a secretory phenotype, which may cause inflammation. We hypothesize that senescence in the healthy brain, caused by whole brain radiotherapy (WBRT), plays an important role in cognitive problems. MATERIAL AND METHODS In this pilot experiment the effect of three different dosages (12, 30 and 60 Gy) of fractionated WBRT was assessed at different intervals after irradiation using male C57BL/6JRj mice. We performed senescence associated β-glucosidase (SA-β-gal) staining, cytokine ELISA assays, RT-qPCRs and immunohistochemistry to identify cellular senescence in the healthy brain. RESULTS Unexpectedly, no clear indications of induced cellular senescence in the brain could be observed by assessing SA-β-gal, cytokines and senescence markers on RNA and protein level. However, we found persistent DNA damage foci, microglial activation, a reduction in oligodendrocyte precursor cells and neurogenesis in the subvertricular zone. CONCLUSION No clear evidence for cellular senescence after WBRT was detected in the mouse brain, whereas profound effects were found on glia, neurogenesis and DNA damage. Difficulties in detecting cellular senescence might be explained by differences in presence of so-called markers for cellular senescence in the brain, or the rare nature of senescence in vivo. In future studies neurobiological changes will be assessed at later time points after WBRT, using a senescence reporter mouse and will be combined with behavioral studies.